Airbus S.A. and Rolls-Royce PLC have cancelled their hybrid-electric aircraft development program, called E-Fan X, with Airbus CTO Grazia Vittadini stating the decision was "undoubtedly necessary" as the partners "evaluate and reprioritize (projects) to ensure alignment with our ambitions".
The aircraft was conceived to have a turbofan engine running on jet fuel, powering a generator that fuels an electric engine -- and stores surplus energy in a series of batteries that provide reserve power for take-offs and landings.
E-Fan X started in 2017 as a partnership of Airbus, Rolls-Royce, and Siemens, though Rolls acquired Siemens' electric propulsion technology business in 2019. Their plan had been to conduct a demonstrator flight this year, with an Airbus BAe 146 flying testbed outfitted with an electric motor in place of one of its four gas turboshaft engines. The electric engine was to be controlled and integrated with a 4,400-lb battery.
Once that technology had been “matured,” a second gas turbine was to be replaced with another electric motor.
A test flight had been projected during 2021.
Rolls-Royce CTO Paul Stein stated that it had become clear to both partners "that the actual requirement to carry out a test flight with all the elements integrated is not critical at this time. As an aircraft, E-Fan X was always designed to be a demonstrator only and never for actual use as a product in service."
"When we launched the E-Fan X project in 2017, we set out with the ambition to push the limits by testing disruptive technologies in a game-changing approach to future aircraft" Vittadini stated. "And we did just that: E-Fan X has shattered pre-conceived notions of what is possible in future flight. This helped us to pave the way for an industry-wide decarbonization movement of which we’re proud to take the lead."
She listed various hybrid-electric propulsion achievements (hybrid architectures, high-voltage systems, and batteries) as "technology bricks" that Airbus will continue to develop.